Download Water - soluble vitamins

VITAMINS
Vitamins: Any of various organic compounds that are needed in small amounts
for normal growth and activity of the body. Most vitamins cannot be synthesized
by the body, but are found naturally in foods obtained from plants and animals.
Vitamins: are either water - soluble or fat - soluble. Most water - soluble
vitamins, such as the vitamin B complex, act as catalysts and coenzymes in
metabolic processes and energy transfer and are excreted fairly rapidly. Fat soluble vitamins, such as vitamins A, D, and E are necessary for the function or
structural integrity of specific body tissues and membranes and are retained in the
body.
A- Fat – soluble vitamins:
1- Vitamin D,
2- Vitamin E,
3- Vitamin A, and
4- Vitamin K,
B- Water - soluble vitamins:
1- Folate (folic acid),
2- vitamin B12,
3- biotin, vitamin B6,
4- niacin,
5- thiamin,
6- riboflavin,
7- pantothenic acid, and
8- vitamin C (ascorbic acid),
1- Vitamin D (sunshine vitamin) : Vitamin D refers to a group of fat soluble secosteroids responsible for increasing intestinal absorption of
calcium, iron, magnesium, phosphate, and zinc. In humans, the most
important compounds in this group are vitamin D3 (also known as
cholecalciferol) and vitamin D2 (ergocalciferol). Cholecalciferol and
ergocalciferol can be ingested from the diet and from supplements. Very few
foods contain vitamin D; synthesis of vitamin D (specifically cholecalciferol)
in the skin is the major natural source of the vitamin. Dermal synthesis of
vitamin D from cholesterol is dependent on sun exposure (specifically UVB
radiation).
UVB: The center of this confusion is the sun's ultraviolet A (long -wave) and
ultraviolet B (shortwave) rays.
Secosteroids: is a type of steroid with a "broken" ring. The word secosteroid
derives from the verb Latin: secare meaning "to cut" and Latin: stere of
steroid, meaning "solid, three-dimensional". Secosteroids are alternatively
described as a subclass of steroids or derived from steroids.
Vitamin D serves several important functions in the body. These
include:
1- promoting calcium absorption
2- maintaining normal calcium and phosphate levels
3- promoting bone and cell growth
4- reducing inflammation
Vitamin D deficiency doesn’t always cause symptoms. When it
does, some of the symptoms may include:
1- Difficulty thinking clearly.
2- Bone pain.
3- Frequent bone fractures.
4- Muscle weakness.
5- Soft bones that may result in deformities.
6- Unexplained fatigue.
Vitamin D deficiencies can cause short – term symptoms and long – term
complications.
Several factors have contributed to the rising incidence of
vitamin D deficiency. These include:
1- wearing sunscreen (sun screen blocks the sun’s ability to stimulate
vitamin D production).
2- not spending enough time outside.
3- having darkly pigmented skin, which won’t absorb the sun’s rays as well
exclusively breast-feeding babies for prolonged time periods.
4- being obese, which typically raises your vitamin D requirements
Some people are born without the ability to process vitamin D.
Vitamin D deficiency has been shown to play a role in almost
every major disease. This includes:
1- Osteoporosis and Osteopenia (reduced bone mass of lesser severity than
osteoporosis).
2- Varieties of Cancer (including breast, prostate and colon (.
3- Heart disease.
4- High blood pressure.
5- Obesity.
6- Gout.
7- Depression and Seasonal Affective Disorder.
8- Alzheimer’s Disease.
9- Chronic fatigue syndrome.
10- Fibromyalgia.
2-Vitamin E (Alpha - tocopherol; Gamma - tocopherol) : Vitamin E is
a fat-soluble vitamin, which plays a role as an antioxidant in the body. It also
helps to prevent free radical damage to specific fats in the body that are critical
for our health.
Vitamin E: is found in many foods including certain oils, nuts, poultry,
eggs, fruits and wheat germ oil. It is also available as a supplement.
Function of vitamin E :
Vitamin E is an antioxidant. This means it protects body tissue from
damage caused by substances called free radicals, which can harm cells,
tissues, and organs.
-7
2- The body also needs vitamin E to help keep the immune system strong
against viruses and bacteria.
3- Vitamin E is also important in the formation of red blood cells and it
helps the body use vitamin K. It also helps widen blood vessels and keep
blood from clotting inside them.
4- Cells use vitamin E to interact with each other and carry out many
important functions.
5- Whether vitamin E benefits include treating and preventing diseases of the
heart and blood vessels; such as chest pains, high blood pressure, and
blocked or hardened arteries.
6- can prevent cancer, dementia, liver disease, and stroke still requires
further research.
7- is an important vitamin that is required for the proper function of many
organs in the body. They are believed to play a role in certain conditions
related to aging and is extremely useful in naturally slowing aging.
Symptoms and Signs of Vitamin E deficiency:
The main symptoms of vitamin E deficiency are:
1- Mild hemolytic anemia.
2- Nonspecific neurologic deficits.
3- Vitamin E deficiency may contribute to retinopathy of prematurity (also
called retrolental fibroplasia) in premature infants.
4- In adults with malabsorption, vitamin E deficiency very rarely causes
spinocerebellar ataxia because adults have large vitamin E stores in adipose
tissue.
5- Low levels of vitamin E can cause many digestive system problems,
which will lead to poor absorption of nutrients from the digestive tract. This
leads to diseases in pancreas, liver, gall bladder etc.
Vitamin E Deficiency Diseases:
1- Anaemia: Vitamin E deficiency can cause birth defects of red blood cells .
(RBCs) are required for haemoglobin to transport oxygen to other parts of
the body., hemolytic anaemia, and degradation of the red blood cells.
2- Poor Balance: Vitamin E deficiency also leads to central nervous system
breakdown, poor reflexes, nerve degeneration of the hands, legs, arms and
feet, impaired coordination, and loss of balance.
3- Pain, tingling, loss of sensation, gastrointestinal diseases.
4-Dry hair or loss of hair.
5- Slow tissue healing.
6 - Cancer.
7- Atherosclerosis.
9- Blindness.
10- Fertility Problems.
3- Vitamin A: A general term for a group of compounds that includes
provitamin A carotenoids (found in foods that come from plants) and retinol
(preformed vitamin A found in foods that come from animals). The body can
use retinol to make retinal and retinoic acid (other forms of vitamin A).
Vitamin A plays an important role in vision, bone growth, reproduction,
immunity, cell development, and skin health. Vitamin A is found in some
foods, including eggs, liver, milk, cheese, leafy green vegetables (such as
spinach, kale, turnip greens, collards, and romaine lettuce), broccoli, dark
orange fruits and vegetables (such as apricots, carrots, pumpkin, sweet
potatoes, papaya, mango, and cantaloupe), and red bell pepper.
Functions of vitamin A
Vitamin A plays a role in a variety of functions throughout the body, such as:
1- Vision.
2- Gene transcription.
3- Immune function.
4- Embryonic development and reproduction.
5- Bone metabolism.
6- Haematopoiesis.
7- Skin and cellular health.
8- Antioxidant activity.
Vitamin A deficiency:
1- Primary vitamin A deficiency is usually caused by
- Prolonged dietary deprivation:
- Xerophthalmia due to primary deficiency is a common cause of blindness
among young children in developing countries.
1-Secondary vitamin A deficiency may be due to:
A- Decreased bioavailability of provitamin A carotenoids
B- Interference with absorption, storage, or transport of vitamin A
Vitamin A deficiency signs and symptoms:
1- Impaired dark adaptation of the eyes, which can lead to night blindness, is
an early symptom of vitamin A deficiency.
2- Xerophthalmia (which is nearly pathognomonic) results from
keratinization of the eyes. It involves drying (xerosis) and thickening of the
conjunctivae and corneas.
3- Superficial foamy patches composed of epithelial debris and secretions on
the exposed bulbar conjunctiva (Bitot spots) develop.
4- In advanced deficiency, the cornea becomes hazy and can develop
erosions, which can lead to its destruction (keratomalacia)
5- Keratinization of the skin and of the mucous membranes in the
respiratory, GI, and urinary tracts can occur. Drying, scaling, and follicular
thickening of the skin and respiratory infections can result.
6- Immunity is generally impaired
7- Growth retardation and infections are common among children. Mortality
rate can exceed 50% in children with severe vitamin A deficiency.
4- Vitamin K:
Functions of vitamin K:
1- Preventing bleeding problems in newborns with low levels of vitamin K
(hemorrhagic disease).
2- Treating and preventing bleeding problems in people with low levels of
the blood clotting protein prothrombin.
3- An inherited bleeding disorder called vitamin K-dependent clotting factors
deficiency (VKCFD). Taking vitamin K by mouth or injecting it
intravenously helps prevent bleeding in individuals with VKCFD.
4- Reversing the effects of
too much warfarin used to prevent blood
clotting. Taking vitamin K1 by mouth or as in injection into the vein can
counteract too much anticoagulation caused by warfarin.
5- Taking vitamin K along with warfarin also seems to help stabilize blood
clotting time in people taking warfarin, especially those who have low
vitamin K levels.
Signs and Symptoms of vitamin K deficiency:
The signs and symptoms associated with vitamin K deficiency may
include:
1- Easy bruising.
2- Oozing from nose or gums.
3- Excessive bleeding from wounds, punctures, and injection or surgical
sites.
4- Heavy menstrual periods.
5- Bleeding from the gastrointestinal (GI) tract.
6- Blood in the urine and/or stool.
7- Increased prothrombin time (PT).
Causes of Vitamin K Deficiency
The most common causes of vitamin K deficiency are:
1- insufficient dietary intake,
2- inadequate absorption,
3-decreased storage of the vitamin due to liver disease,
4-it may also be caused by decreased production in the intestine
5- it is often seen in cancer patients on chemotherapy, chronic dialysis
patients, and patients who are at risk for malnutrition, such as those with a
poor diet associated with alcohol or drug abuse.
6- Malabsorption, especially impaired absorption of fats due to diseases such
as cystic fibrosis, celiac disease, chronic pancreatitis or Crohns disease, may
cause vitamin K deficiency.
7- Choleostatic liver diseases such as a bile duct obstruction or primary
biliary cirrhosis can also lead to malabsorption and a deficiency in vitamin K.
Water soluble vitamins:
Water - soluble vitamins travel freely through the body, and excess amounts usually are
excreted by the kidneys. The body needs water-soluble vitamins in frequent, small
doses. These vitamins are not as likely as fat-soluble vitamins to reach toxic levels. But
niacin, vitamin B6, folate, choline, and vitamin C have upper consumption limits.
Vitamin B6 at high levels over a long period of time has been shown to cause
irreversible nerve damage.
Water-soluble vitamins
B- complex
Energy – releasing vitamins:
1- Thiamine (vit B1)
2- Riboflavin ( vit. B2)
3- Niacin (vit B3)
4- Biotin.
5- Pantothenic acid.
Haematopoitic vitamins:
1.Folic acid.
2.Vit. B12
Other vitamins
1.Pyridoxine (vit B6)
2.Pyridoxal.
3.Pyridoxamine.
Thiamine (vitamine B1)
The active form of vit B1 is diphosphate, which is converted by ATP –
dependant enzyme present in the brain and liver called diphospho
transferase.
Thiamine pyrophosphotase is a coenzyme serves in enzymatic reactions:
1.Transketolase reaction; that is necessary for the formation of
glyceraldehydes 3-p
2.It is also involved in citric acid cycle.
Deficiency of thiamine:
1- Periphral neuropathy and anorexia, odema, cardiovascular and muscular
degeneration.
2- Beri-Beri disease is a severe deficiency of thiamine.
RIBOFLAVIN (Vitamine B2 )
The active forms of riboflavin are:
1.Flavin mononucleotide (FMN)
2.Flavin adenine dinucleotide (FAD).
FMN is formed by ATP-dependant phosphorylation of riboflavin; while
FAD is synthesized by a further reaction with ATP in which the AMP
moiety of ATP is transferred to FMN.
Its function as coenzymes;
Deficiency of Riboflavin:
Include:
1. Dermatitis.
2. Cheilosis. (Fissuring at the corners of the mouth).
3. Glossitis( the tongue appears smooth and purplish).
Niacin (Nicotinic acid and Nicotinamide) :
Are both coenzymes for many oxido-reductase . They act with enzymes
dehydrogenase; involved in carbohydrate,lipids and aminoacids
metabolismas in the citric acid cycle.
Distibution :
It is found in most animal and plant food
Clinical indication for Niacin;
A .Deficiency of Niacin leads weight loss, dermatitis, digestive disorders.
,diarrhea.and depression(central nervous system).
B. Treatment of hyperlipidemia
Nicotinic acid is used for lowering serum cholesterol, due to inhibition of
free fatty acid from adipose tissue.
Biotin
It is a coenzyme in carboxylation reactions in which it serves as a carrier of
activated carbon dioxide
Deficiency of Biotin
Biotin deficiency does not occur naturally because the vitamin is widely
distributed in food.
PANTOTHENIC ACID
The active form of it is the [ coenzyme A] . CoA occurs in citric acid cycle.
Fatty acid synthesis, oxidation and acylation reaction and cholesterol
synthesis. Its functions in the transfer of acyl groups.
Pyridoxine( vitamine B6)
Vitamin B6 consist of 3 closely related naturally occurring pyridine
derivatives.
1.Pyridoxine
2.Pyridoxal.
3.Pyridoxamine.
All these three derivatives are equal in activity as precursors for the
coenzyme ,this coenzyme helps many enzyme of amino acid metabolism.
The reactions are transamination, Deamination, Decarboxylation and
condensation.
FOLIC ACID
Folacin has the biochememical activity of folic acid. Yeast, liver , leafy
vegetables are the major sources for folic acid.
Active folate: is the tetrahydrofolate which is formed by a reduction occurs
in the intestinal cells by the enzyme folate reductase,in this reaction NADPH
is used as a donor for [H].
Clinical indication:
Folic acid deficiency result in growth failure and megaloblastic anemia
(decrease DNA synthesis): this state may be caused by:
1. Increased demand with adequate loss of folate such as in pregnancy and
lactation.
2. Poor absorption due to pathological disorder of the small intestine.
3. Alcoholism.
Vitamin B12 (cobalamine)
It is synthesized by microorganisms , liver is also a good source for vitamin
B12 ,the commercial preparation is cyanocobalamin.
The active coenzyme forms of Vit B12 are :
1- Methylcobalamine.
2- Deoxyadenosylcobalamine which help in the conversion of
methylmalanoyl-CoA to succinyl CoA (in the citric acid cycle).
Absorption of Cobalamine:
Mammals absorbed cobalamine using aspecialized transport system.,here the
stomach secret a glycoprotein called INTRINSIC FACTOR (IF),which
binds cobalamine to the intestinal lumen.
Nutritional deficiency of cobalamine is rare except in strict vegetarian;as
this vitamin is found in all animal sources.
Methylcobalamine is coenzyme in the combined conversion of :
1. Homocysteine to methanionine
and
2. Methyltetrahydrofolate to tetrahydrofolate
Ascorbic acid (vitamin C):
Vit C act as coenzyme Acts as a donor of reducing equivalents and it is
oxidized Dehydroascorbic acid, which is a source of vitamin C.
Clinical Indication of Vit C:
1-Deficiency of Vit C results in scurvy
2. Prevention of chronic diseases:
Vitamin C act as antioxidants (i.e inactivate the free radicals).
Water soluble vitamins
Water soluble vitamins
Thiamine (vitamin B1)
Function
Part of an enzyme needed for energy metabolism;
important to nerve function.
Riboflavin (vitamin B2)
Part of an enzyme needed for energy metabolism;
important for normal vision and skin health.
Niacin (vitamin B3)
Part of an enzyme needed for energy metabolism;
important for nervous system, digestive system,
and skin health.
Pantothenic acid
Part of an enzyme needed for energy metabolism.
Biotin
Part of an enzyme needed for energy metabolism.
Pyridoxine (vitamin B6)
Part of an enzyme needed for protein metabolism;
helps make red blood cells.
Folic acid
Part of an enzyme needed for making DNA and
new cells, especially red blood cells.
Cobalamin (vitamin B12)
Part of an enzyme needed for making new cells;
important to nerve function.
Ascorbic acid (vitamin C)
Antioxidant; part of an enzyme needed for
protein metabolism; important for immune
system health; aids in iron absorption.
Water soluble vitamins deficiency disease
Water soluble vitamins
Thiamine (vitamin B1)
Disease
Rare- Beriberiloss of muscle function, nerve
damage, mental confusion.
Riboflavin (vitamin B2)
Uncommonanemia mouth sores, sore throat,
swelled mucous membranes, and skin disorders.
Niacin (vitamin B3)
Pellagra is characterized by the 4 D’s
Dermatitis, Diarrhea, Dementia, and Death
Pantothenic acid
Very rare- only seen in severe malnutrition
Symptoms are headache, fatigue, burning
and numbness of feet.
Biotin
Rare but symptoms include hair loss
dry scaly skin, cheilitis, fatigue and depression.
Pyridoxine (vitamin B6)
,uncommon but includes convulsions, nausea
depression, anemia, and dermatitis.
Folic acid
anemia, birth defects, and slowed growth
during growing phase. It is very important for
women of childbearing age to get enough folic
acid even if not expecting to be pregnant.
Cobalamin (vitamin B12)
Pernicious anemiarare, symptoms are anemia,
,fatigue, weight loss, neurological damage
and cognitive impairment.
Ascorbic acid (vitamin C)
,Scurvy, symptoms are bleeding
bruising easily, hair and teeth loss, joint pain and
swelling and in severe cases death.